Process for preparing synthetic petrolatum

ABSTRACT

1. A PROCESS FOR PREPARING A SYNTHETIC PETROLATUM WHICH INVOLVES PASSING ALPHA OLEFINS HAVING 30 OR MORE CARBON ATOMS OVER SILICA ALUMINA AT A TEMPERATURE OF ABOUT 200* TO ABOUT 260*C.

3,843,511 f 1 PROCESS FOR PREPARING SYNTHETIC PETROLATUM Charles M. Selwitz, Monroeville, Pa., assignor to Gulf Research & Development Company, Pittsburgh, Pa. No Drawing. Filed Oct. 24 1973, Ser. No. 409,244

United States Patent Ofiice 3,843,511 Patented Oct. 22, 1974 of ethylene in the presence of triethylalurninum, as defined in said patent to Fernald et al., having an average a set forth below. in Table I.

Int. Cl. C07c 3/02, 5/22,- Cg 11/04, 43/02Cl TABLE I 208-120 6 aims Carbon-number Weight percent 10 0.12 ABSTRACT OF THE DISCLOSURE I 22 0.63 A process for preparing synthetic petrolatum which in- 24 volves passing alpha olefins having or more carbon 12-57 atoms over silica alumina at a temperature of about 200 16'27 to about 260 C. 32 1587 This invention relates to a process for preparing synthetic petrolatum from alpha olefins having 30 or more 38 carbon atoms. Petrolatum can be used as a lubricant, as 40 a waterproofing agent, as a medical unguent, etc. 20 42 The process for preparing synthetic petrolatum defined 44 and claimed herein involves passing an alpha olefin or a mixture of alpha olefins having 30 or more carbon atoms, 48 generally no higher than 50 carbon atoms, but preferably having from 30 to 40 carbon atoms, over silica alumina 25 In the above mixture 21.57 weight percent of the fraction at a temperature of about 200 to about 260 C., preferhad a carbon number of 28 or less, while 78.43 Weight ably about 220 to about 250 C. at a linear hourly space percent had a carbon number of 30 and above. Also, velocity (volume of alpha olefins per volume of silica 62:5.0 weight percent of the mixture was trans, 675:5.0 aluminum per hour) of about 0.010 to about 20, preferweight percent was alpha and 26.3 5.0 weight percent ably about 0.10 to about 10. Preferably, prior to passage 30 was vinylene (R C=CH The results obtained are tabuover the silica alumina the alpha olefins are heated to a lated in Ta le II.

TABLE II Feed rate, milli- Catalyst Linear liters volume, hourly per Mesh millispace hour Silica alumina used size liters velocity Appearance Properties 10 American Cyanamid AAA silica alumina..- 10 1. 0 Very soft Not analyzed. 30 .do 10 10 do See Table III. 200 do 425 0. 472 softened slightly Not analyzed.

0% H.150 236 0.236 Softer than run No. 3. Do. 200 IIIIIdoI 125' 0. cfr'taaiuum con'site'riifjf. See Table III. 4. 5 Davison silica alumina 1020 30 0. 150 Not softened-. Not anlayzed. 4.5 do 10-20 30 0.150 Somewhat softer. Do. 4.5 .do 10-20 30 0.150 Verysoft D0. 5 American Cyanamid AAA silica alunn 30 0.166 Not softened Do. 5 do 30 0.166 Somewhat softened Do. 5 do 30 0.100 Soft Do.

temperature at which they become liquid, for example, in the range of about 70 to about 100 C. Pressures are preferably atmospheric, although pressures as high as about 100 pounds per square inch gauge (7.03 kilograms per square centimeter) can be used. As a result of the treatment the hard, brittle olefins are converted to a soft, unctuous material suitable as a synthetic Vaseline.

Any of the conventional silica aluminas can be employed. For example, a typical silica alumina will contain from about five to about 95 percent by weight of silica, preferably about 65 to about 85 percent by weight of silica, with substantially all of the rest being alumina. Particle size can be from about live to about 100 mesh, preferably about 10 to about 20 mesh.

Alpha olefins from any source can be used herein. A preferred source of such alpha olefins are those alpha olefins having 30 or more carbon atoms obtained as a result of the polymerization of ethylene in the presence of an alkyl aluminum, such as triethylaluminum, at elevated temperatures and elevated pressures. An example of such procedure is defined in US. Pat. No. 3,482,000 to Fernald et al. dated Dec. 2, 1969, which patent is hereby incorporated in by reference.

The process can further be illustrated by the following. An alpha olefin fraction obtained by the polymerization The comparison of the properties of the charge with the products obtained in Runs Nos. 2 and 6 above and with petrolatum is set forth below in Table III.

The above illustrates that the treated product obtained herein falls easily within the specifications of natural petrolatum. Although no analysis was made of the products made in Runs Nos. 1, 4, 9, 11 and 12, the appearance and feel of the product was that of natural petrolatum. The products of Runs Nos. 3, 5, 7, 8 and 10 prepared at temperatures outside the operative ranges herein proved to be unacceptable as petrolatum substitutes.

The results obtained herein are unexpected. In US. Pat. No. 2,620,365 Anderson states that when a high-boiling alpha olefin, such, for example, as l-octadecene, is treated with an active silica alumina catalyst of the conventionally employed in catalytic cracking operations at -a---- temperature in the range of about 300 to 650 F. (149 to 343 0.), its melting point'(which may be considered as its pour point) may be lowered by as much as 50 F. (about 28 depending upon the severity of the treatment. On this basis one skilled in the art, who would want to convert an alpha olefin to synthetic petrolatum, would not treat a solid, crystalline alpha olefin with silica alumina, for to do so would so reduce its melting point as to render the same a liquid rather than a soft, tacky, unctuous material suitable as a synthetic petrolatum. Surprisingly, as the above data show, the product obtained herein has a melting point on the same order as the charge but still has the same physical properties as petrolatum.

Obviously, many modifications and variations of the invention, as hereinabove set forth, can be made without departing from the spirit and scope thereof, and, theretore, only such limitations should be imposed as are indicated in the appended claims. a 1

I claim: 1 a

1. A process for preparing a synthetic petrolatum which involves passing alpha olefins having 30 or more carbon atoms over silica alumina at a temperature of about 200 to about 260 C.

2. The process of claim 1 wherein said temperature is in the range of about 220 to about 250 C.

v 3. fheprocess of claim l wherein a mixture of alpha olefins in the range of to carbon atoms are passed References, Cited I UNITED STATES PATENTS 2,620,365 12/1952 Anderson 260-683.l5 3,482,000 12/ 1969 Fernald et a1 260683.15

DELBERT E. GANTZ, Primary Examiner G. E. SCHMITKONS, Assistant Examiner U.S. c1. X.R. 

1. A PROCESS FOR PREPARING A SYNTHETIC PETROLATUM WHICH INVOLVES PASSING ALPHA OLEFINS HAVING 30 OR MORE CARBON ATOMS OVER SILICA ALUMINA AT A TEMPERATURE OF ABOUT 200* TO ABOUT 260*C. 